From 781e3d7ad82c30656e204ecec4635079807e41bd Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Wed, 29 Jun 2022 16:23:41 -0700
Subject: [PATCH] [RISCV] Pre-commit tests for D128869. NFC

---
 llvm/test/CodeGen/RISCV/rv64i-shift-sext.ll | 94 +++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/llvm/test/CodeGen/RISCV/rv64i-shift-sext.ll b/llvm/test/CodeGen/RISCV/rv64i-shift-sext.ll
index f52f4eef4f53..af4e4b233470 100644
--- a/llvm/test/CodeGen/RISCV/rv64i-shift-sext.ll
+++ b/llvm/test/CodeGen/RISCV/rv64i-shift-sext.ll
@@ -82,3 +82,97 @@ define i64 @test6(i32 signext %a, i32 signext %b) nounwind {
   %4 = ashr i64 %3, 16
   ret i64 %4
 }
+
+; The ashr+add+shl is canonical IR from InstCombine for
+; (sext (add (trunc X to i32), 1) to i32).
+; That can be implemented as addiw make sure we recover it.
+define i64 @test7(i32* %0, i64 %1) {
+; RV64I-LABEL: test7:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a1, 32
+; RV64I-NEXT:    li a1, 1
+; RV64I-NEXT:    slli a1, a1, 32
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    srai a0, a0, 32
+; RV64I-NEXT:    ret
+  %3 = shl i64 %1, 32
+  %4 = add i64 %3, 4294967296
+  %5 = ashr exact i64 %4, 32
+  ret i64 %5
+}
+
+; The ashr+add+shl is canonical IR from InstCombine for
+; (sext (sub 1, (trunc X to i32)) to i32).
+; That can be implemented as (li 1)+subw make sure we recover it.
+define i64 @test8(i32* %0, i64 %1) {
+; RV64I-LABEL: test8:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a1, 32
+; RV64I-NEXT:    li a1, 1
+; RV64I-NEXT:    slli a1, a1, 32
+; RV64I-NEXT:    sub a0, a1, a0
+; RV64I-NEXT:    srai a0, a0, 32
+; RV64I-NEXT:    ret
+  %3 = mul i64 %1, -4294967296
+  %4 = add i64 %3, 4294967296
+  %5 = ashr exact i64 %4, 32
+  ret i64 %5
+}
+
+; The gep is here to introduce a shl by 2 after the ashr that will get folded
+; and make this harder to recover.
+define signext i32 @test9(i32* %0, i64 %1) {
+; RV64I-LABEL: test9:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a1, a1, 32
+; RV64I-NEXT:    lui a2, 4097
+; RV64I-NEXT:    slli a2, a2, 20
+; RV64I-NEXT:    add a1, a1, a2
+; RV64I-NEXT:    srai a1, a1, 30
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    lw a0, 0(a0)
+; RV64I-NEXT:    ret
+  %3 = shl i64 %1, 32
+  %4 = add i64 %3, 17596481011712 ; 4097 << 32
+  %5 = ashr exact i64 %4, 32
+  %6 = getelementptr inbounds i32, i32* %0, i64 %5
+  %7 = load i32, i32* %6, align 4
+  ret i32 %7
+}
+
+; The gep is here to introduce a shl by 2 after the ashr that will get folded
+; and make this harder to recover.
+define signext i32 @test10(i32* %0, i64 %1) {
+; RV64I-LABEL: test10:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a1, a1, 32
+; RV64I-NEXT:    lui a2, 30141
+; RV64I-NEXT:    addiw a2, a2, -747
+; RV64I-NEXT:    slli a2, a2, 32
+; RV64I-NEXT:    sub a1, a2, a1
+; RV64I-NEXT:    srai a1, a1, 30
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    lw a0, 0(a0)
+; RV64I-NEXT:    ret
+  %3 = mul i64 %1, -4294967296
+  %4 = add i64 %3, 530242871224172544 ; 123456789 << 32
+  %5 = ashr exact i64 %4, 32
+  %6 = getelementptr inbounds i32, i32* %0, i64 %5
+  %7 = load i32, i32* %6, align 4
+  ret i32 %7
+}
+
+define i64 @test11(i32* %0, i64 %1) {
+; RV64I-LABEL: test11:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a1, 32
+; RV64I-NEXT:    li a1, -1
+; RV64I-NEXT:    slli a1, a1, 63
+; RV64I-NEXT:    sub a0, a1, a0
+; RV64I-NEXT:    srai a0, a0, 32
+; RV64I-NEXT:    ret
+  %3 = mul i64 %1, -4294967296
+  %4 = add i64 %3, 9223372036854775808 ;0x8000'0000'0000'0000
+  %5 = ashr exact i64 %4, 32
+  ret i64 %5
+}